| ### Seventh Tractate ### ON COMPLETE TRANSFUSION ###  |

| #### Chapter 1 |

| #### #### Some enquiry must be made into what is known as the complete transfusion of material substances. #### Is it possible that fluid be blended with fluid in such a way that each penetrate the other through and through? or- a difference of no importance if any such penetration occurs- that one of them pass completely through the other? #### Those that admit only contact need not detain us. They are dealing with mixture, not with the coalescence which makes the total a thing of like parts, each minutest particle being composed of all the combined elements. #### But there are those who, admitting coalescence, confine it to the qualities: to them the material substances of two bodies are in contact merely, but in this contact of the matter they find footing for the qualities of each. #### Their view is plausible because it rejects the notion of total admixture and because it recognizes that the masses of the mixing bodies must be whittled away if there is to be mixture without any gap, if, that is to say, each substance must be divided within itself through and through for complete interpenetration with the other. Their theory is confirmed by the cases in which two mixed substances occupy a greater space than either singly, especially a space equal to the conjoined extent of each: for, as they point out, in an absolute interpenetration the infusion of the one into the other would leave the occupied space exactly what it was before and, where the space occupied is not increased by the juxtaposition, they explain that some expulsion of air has made room for the incoming substance. They ask further, how a minor quantity of one substance can be spread out so as to interpenetrate a major quantity of another. In fact they have a multitude of arguments. #### Those, on the other hand, that accept "complete transfusion," might object that it does not require the reduction of the mixed things to fragments, a certain cleavage being sufficient: thus, for instance, sweat does not split up the body or even pierce holes in it. And if it is answered that this may well be a special decree of Nature to allow of the sweat exuding, there is the case of those manufactured articles, slender but without puncture, in which we can see a liquid wetting them through and through so that it runs down from the upper to the under surface. How can this fact be explained, since both the liquid and the solid are bodily substances? Interpenetration without disintegration is difficult to conceive, and if there is such mutual disintegration the two must obviously destroy each other. #### When they urge that often there is a mixing without augmentation their adversaries can counter at once with the exit of air. #### When there is an increase in the space occupied, nothing refutes the explanation- however unsatisfying- that this is a necessary consequence of two bodies bringing to a common stock their magnitude equally with their other attributes: size is as permanent as any other property; and, exactly as from the blending of qualities there results a new form of thing, the combination of the two, so we find a new magnitude; the blending gives us a magnitude representing each of the two. But at this point the others will answer, "If you mean that substance lies side by side with substance and mass with mass, each carrying its quantum of magnitude, you are at one with us: if there were complete transfusion, one substance sinking its original magnitude in the other, we would have no longer the case of two lines joined end to end by their terminal points and thus producing an increased extension; we would have line superimposed upon line with, therefore, no increase." #### But a lesser quantity permeates the entire extent of a larger; the smallest is sunk in the greatest; transfusion is exhibited unmistakably. In certain cases it is possible to pretend that there is no total penetration but there are manifest examples leaving no room for the pretence. In what they say of the spreading out of masses they cannot be thought very plausible; the extension would have to be considerable indeed in the case of a very small quantity [to be in true mixture with a very large mass]; for they do not suggest any such extension by change as that of water into air. ####  |